1. Technical Field
Aspects of the present disclosure relate to medical processing devices and, in particular, to an adipose-derived stem cell processing system and method.
2. Discussion of Related Art
Stem cells, such as adipose-derived stem cells (ASCs), may be harvested from various parts of the human body, such as adipose tissue. ASCs are easily harvested by liposuction and, in most patients, a large quantity of ASCs can be obtained without substantial harm to the donor. It has been shown that a human lipoaspirate contains pluripotent and multipotent cells and may represent an alternative stem cell source to bone marrow-derived mesenchymal stem cells and embryonic stem cells. ASCs are capable of proliferation in monolayer culture and multilineage differentiation in response to inductive conditions, and thus have potential clinical application.
Interest in the field of regenerative medicine has shown promise in treating conditions, such as Parkinson's disease, Alzheimer's disease and cancers. This is accomplished through the implantation of stem cells which can be found in both embryonic and adult tissues. While much of the focus on stem cell shortage has focused on the embryonic sources, harvesting of embryonic stem cells has resulted in a great deal of ethical and political debate. Therefore, many scientists have turned to adult sources of stem cells, including adipose tissue, brain tissue, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium, and testes.
Adipose tissue has been identified as an endocrine organ, in addition to its originally identified purpose of energy storage. By secreting bioactive molecules, called adipokines, this tissue plays an active role in the regulation of several bodily functions. Cellular content of adipose tissue includes specialized cells such as adipocytes and a stromal vascular fraction containing pre-adipocytes (which can differentiate into adipocytes), fibroblastic cells, endothelial cells, macrophages, and lymphocytes.
An adult stem cell is thought to be an undifferentiated cell, found among differentiated cells in a tissue or organ, that can renew itself and can differentiate to yield some or all of the major specialized cell types of the tissue or organ. Typically, there are a very small number of stem cells in each tissue, and once removed from the body generation of large quantities of stem cells is difficult. A need therefore exists to find a safe and efficient means of harvesting these stem cells from live tissue.
Current methods of harvesting mesenchymal stem cells from adipose tissue have severe drawbacks which limit their efficacy and both result in significant destruction of the original tissue. Such methods face problems with enzyme source, consistency, concentration, potency and manufacture. In one such method, mesenchymal stem cells are removed from adipose tissue through the use of an enzymatic digestion step. The enzyme must be diluted and washed from the cell culture when digestion is complete, but trace levels can remain. These enzymes may also damage the integrity of the cell walls. Therefore, there is a need for a method which will not significantly harm the surrounding adipose tissue or extracellular matrix during the stem cell dissociation; where the final stem cell product will have many of the original cells intact.
Other methods present issues with respect to low yield and cells rupturing, which causes damage to otherwise healthy adipose tissue. Additionally, such methods make it difficult to maintain an aseptic process and are open, which increases the risk of contamination and infection. Therefore, there is a general need in the field for a method of safely and efficiently harvesting regenerative cells and ASCs from adipose tissue, without the use of any enzymes and without altering the structural ability of the adipose tissue for repair or reconstruction.
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